Furnace



(No Model.)

No.l 529,795.

N. JOHNSON.

FURNAGE.

' 4 sheets-sheen 1.

Patented NGV. 27, 1894.

Ll jE I l I ne Nonms mires co. mmuuTHo,.wAsuINn1ou n c mara/f7 (NoModel.) f 4'Sheets-Sheet 2.` N. J OHNSON. FUBfNAGE.

No. 529,795. Patented Nov. 27, 1894.

Mwoac-a {g1/wanton @Hoz-*new We@ fue Nqnms PETERS co. moraumo.,WASHINGTON, D. c,

N. JOHNSON.

4 Sheets-Sheet 3.

(No Model.)

FU'RNAGN.

No. 529,795. Patented N0v..27, 1894.

i auen/Cda 4Sheets'fSheet 4. N. JOHNSON. 'FURNAOR (No Model.)

Patented Nov. 2'7,O 1894.

IVIrI f f f f f n f f f f f 4 4..

l T l I I I l l I I I l l l l T IIIIIIII l -Il llnnunullh 1111 l lwit/woon UNITED' STATE-S- ANILS JOHNSON, OF ST. LOUIS, MISSOURI.

vQIATENT OFFICE.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 529,795, dated November27, 1 894. Application filed August 22,1893. Serial No. 483,774. (Nomodel.)

To all whom, it may concern:

Be it knownA that I, NILS JOHNSON, of St. Louis, Missouri, have made anew and useful Improvement in Furnaces, of which the following is afull, clear, and exact description. The improvement relates to furnacesin which means are employed for abating the smoke and for .morethoroughly consuming the fuel. .While not exclusively adapted thereto,the improvement can be used advantageously in a steam boiler furnace,and it isr in connection with such a construction that it is hereillustrated.

It consists mainly in maintaining a curtain, so to speak, of aircrosswise in the furnace and extending fromjthe top of the furnacedownward to meet the furnace tire at a point forward of the rear endthereof, and so as to cross the course of the escaping, more orV less,unconsumed portion of the fuel, and, by providing an ample supply/ofoxygen, enabling `the more complete, if not thorough, consumption of thefuel.

To enable the improvement to be further carried out the air is caused toeffectively cooperate with the incandescent portion of the furnace fire.The air is also so introduced as to be well mixedwith the unconsurnedgaseous fuel. p y Y The annexed drawings, making part of thisspecification, exhibit the most desirable mode of carrying out theimprovement.v

Figure 1 is a vertical cross section, on the line 1--1 of Fig. 3, ofasteam boiler furnace constructed vaccording to the principle of theimprovement, a battery of two boilers being shown, and the view lookingtoward the front end of the furnace; Fig. l2, a horizontal section,looking upward, on the line 2-2 of Fig. l; Fig. 3, acentral,longitudinal section of the construction shown in Fig. 1; Fig.'4, a top view of the plate used at each side of the furnace to supportthe 'air-pipes; Fig. 5, a vertical section on the line 5--5 of Fig. 4;Figs. 6` and 7, respectively a cross section and a side view of thelower end of the airpipes at one Side of the furnace; Figs. 8 and 9,respectively a plan and side elevation of the grate that is preferablyused to support that portion of the furnace iire whichis directlybeneath the descending air current; Fig. 10, a view analogous to that ofFig. 1 but showing the imthose of Figs. 13 and 14 but showing the ar-vrangement for the single boiler construction.

The same letters of reference denote the same parts.

Fig. 1 represents an application of the improvement to a battery of twoordinary steam boilers A and A'. The setting, B, the furnace or fireplace C, the ash pit D, the bridge wall E, the escape iiue F, and otherparts of the construction, are ofthe usual form saving as modified orsupplemented bythe improvement under consideration. furnace is also ofthe usual nature saving as it is assistedor modified by the use of theimprovement. G G G2'represent passages through which .the air isintroduced into the furnace. They extend across the furnace above thefuel H. They receive air` at their ends and are perforated at variouspoints g, g, to provide outlets for the air to pass from the passagesinto the furnace. These passages may be composed of any suitablematerial, and be of any suitable form, and be supported in any suitablemanner, and one, two, or more of them may be used, and (when more thanone passage is used) they may be arranged closely alongside of eachother, or be spaced more or less apart from each other, and they may bearranged at diierent levels, so long as they serve', either singly oruni'tedly, to deliver air inthe manner described downward to or towardthev burning fuel beneath. I prefer the arrangement shown. That is,ordinary steampipes, properly protected from the.fire,are used, and, fora furnace adapted for a battery of two boilers as in Fig. 1, acombination of three pipes is employed, and they are' arranged above therear portion of the furnace, and closely alongside of' each other, andtheir outlets g are out of line with-each other substantially as shownin Fig. 2, and the pipes aresustained by extending their ends, g', g',downward to rest upon a plate I, Figs. 1, 4, 5, and 13, which in turn isupheld by the crossbar J employed to support the ordinary grate bars K.The pipe ends are enlarged, the end being threaded to receive a nut g2,and the plate I is perforated at t' to admit the air and recessed at i'to receive the enlarged end of the pipe, substantially as shown. Thepipes are pretected from the tire by means of tiles L of refractorymaterial. The tiles are strung on the pipes, and are preferably tonguedand grooved substantially as shown at Z, Z', to interlock with eachother, substantially as shown, and they are perforated at 712 oppositethe outlets in the pipe to provide for the delivery of the air throughthe tile into the furnace.

It is important that the escape from the furnace be entirely between thedescribed air passage or passages and the fire beneath. To this end asuitable partition or wall, M, is constructed above the air passages toprevent escape in that direction from the furnace. The Wall at its lowerend joins, and is preferably adapted to rest upon the tiles L, and itextends thence upward to meet the covering N, substantially as shown.rlhe stirrups m, and suspension rod, m', may be used as shown to aid insustaining the wall and pipes. The pipes and their inclosing tiles alsoserve as a diaphragm to deflect the course of the escaping gasesdownward toward the fire II. The air, in the present instance, entersthe passages, G, rbc., from the ash-pit. It may, however, be otherwisesupplied to the passages. By reason of the natural draft of the furnacethe air is drawn into the passages G, dsc., and thence into the furnace;but, as the air when influenced solely bythe draft referred to tends toescape too readily into or toward the flue F, I employ auxiliary meanswhich co-operate to direct the air more immediately into contact withthe fire, and accordingly steam currents are used, and preferably in thefollowing manner:

O represents a steam pipe taking steam from any suitable source andconducting it to the nozzles o, o', which are arranged, respectively,beneath the inlets fto the air passages G, dsc., and byturning on thesteam the air is forced more vigorously into and through theair-passages and delivered more directly into the vicinity of the fire.A certain amount of steam is also carried to the fire and the heat ofthe furnace is thereby increased. The steam-delivery may be controlledby valves o2 arranged at any desirable point in the steampipe. I haveascertained that a small amount of steam sufces. The air-delivery isalso controllable, and for this purpose I prefer to employ a damper Pwhich serves to open or close an air-chamber p formed, substantially asshown, beneath the inlets to the air-passages and containing the nozzles0, o. The damper is hinged at p' and supported by an arm p2. Theoperation of the damper is indicated by its positions shown respectivelyin the full and broken lines in Fig. 3. suitable amountof air is also,and by the customary means (not shown) admitted to the furnace throughthe doorways c. The airpassages are arranged in front of the bridgeWall, substantially as shown, and the frontface e of the bridge wall ispreferably inclined as shown. This provides an additional space c forthe more incandescent fuel, and in tiri-ng the furnace the green fuel isnot placed beyond the described air-curtain. Beneath and beyond the aircurtain the fuel is incandescent. To promote the incandescence of thefuel the air-supply from beneath the fire is preferably diminished moreimmediately beneath the plane in which the air is delivered downwardfrom the air passages G, &c. For this purpose such a construction as thegrate K', Figs. 1, 3, 8, and 9, is used, and the ordinary grate-bars, K,are stopped off in front of the point referred to, substantially asshown. The nozzles o, 0', and the inner end of the steam' pipe O, arepreferably supported by a stirrup, o5, that is suspended from the plateI. In the present illustration the middle passage G is not provided Withany nozzle, as the air currents introduced through the passages G, G2,operate to draw the air entering through the passage G', more or lessdownward with them.

In Figs. 10, 11, 12, 15 and 16 an adaptation of the improvement to asingle boiler construction is shown. It is substantially similar to thatemployed for a double boiler construe tion. In the present illustration,however, a single, widened air passage, G3, is used in the place ofaseries of air passages as previously described, and the air outlets Z2,from the passage g3 are arranged in a zigzag fashion substantially asshown in Fig. 16 in order to obtain the same effect that is obtained bythe arrangement of air outlets in Fig. 14, that is to enable the air tobe delivered from the air passages in the form of jets which are placedclosely alongside of each other and which preferably lap upon eachother.

The construction shown in Figs. 11, 12, 15 and 16 can be used-in allcases if desired. The plate I', Figs. 12,15, and 1G, is adapted tosupport the widened pipe G3, and it is suitably perforated at t5 andrecessed at i, to admit the air and to support the pipe. In allinstances it is desirable to divide the air passages midway in theirlength, as by means of a partition glo, as thereby the air is deliveredmore satisfactorily in the furnace, and one side or portion of thefurnace can be supplied with a stronger air-current than the other. Theform of pipe which constitutes the air IOO passage G3 may be a casting,and it may be fully closed tothe passage of the product of combustion;but there may be small openings in the wall withoutmateriallyinterfering with the operation of the improvement. The steam beingdirected downward to the Y incandescent fuel is decomposed and a morefavorable combustion of the fuel is thereby I auxiliary air must beprojected forcibly downward from the rear upper part of the furnace orfire place, and to cross the course of ythe fire place gaseous currentand meet the incandescent -fnel at a point forward of the bridge wall.forward upper part of the fire place it does not retard or evenmaterially influence the course that the fire place gaseous currentnaturally takes in passing to the escape. In fact it more or lessfacilitates the escape; and if the air is delivered downward from therear upper part of the lire place to meet thebridge wall it does notencounter the incandescent portion of the fire, nor does itsubstantially retard the escape of the lire place current, and it willnot at all retard it if the downward air current is neutralized by anopposing upward air current. Furthermore, unless the air is projectedwith sufcient force to overpower the influence of the natural draft ofthe fire-place and carry the air downward to meet the incandescent fuelthe ef icient abatement of the smoke will not be accomplished.

I claim- 1. The hereinbefore described method of effecting an increasedconsumption of fuel and the prevention of smoke in furnaces, the

If the air is delivered from the same consisting in obstructing andbreaking up the outgoing current of unconsumed products of Ycombustionby projecting a transverse sheet or curtain of air downwardly upon thefuel from the rear upper part of the firebox at a point in front of thebridge-wall.

2. In a furnace, the combination of the firebox, the bridge-wall in rearthereof, an air passage or passages extending across the upper rear partof the fire-box in front of the vertical plane of the bridge-Wall, andjet orifices leading from said passage into the fireb'ox at a p'ointabove the bed of the fuel; substantially as described.

3. In a furnace, the combination of the firebox, the bridge-wall in rearthereof,`an air passage or passages extending up the sides and acrossthetop of therear part of the iirebox in front of the vertical plane ofthe bridge-Wall, and j et orifices leading from said passage into thefire-box at a point above the bed of the fuel; substantially asdescribed.

4. The combination, in a furnace, of an air passage extending crosswisein the furnace 'forward of the bridge-wall and receiving and deliveringair as described, with means for diminishing the air supply from beneaththe furnace in the vertical plane of said air-passage; substantially asdescribed.

5. The combination, in a furnace, of the pipes and the tiles, said pipeshaving said tiles strung thereon and arranged to form an arch 'overthe/ire-box having a passage through which air and steam are delivereddownward into the furnace; substantially as described.

Witness my hand this 19th day of August,

N ILS JOHNSON. Witnesses:

C. D.y MOODY, A. BONVILLE.

